A former New Orleans police officer fired in 2012 for testing positive for marijuana should get his job back, an appeal court ruled this week.

The NOPD improperly terminated David DeSalvo for violating the city's anti-drug policy because the amount found in his system was too low to merit termination, the Louisiana 4th Circuit Court of Appeal found. The amount of marijuana -- 43 nanograms per milliliter -- was less than the amount that employers are allowed to sanction employees for under state law, the unanimous three-judge panel.

The NOPD, which can appeal the ruling, did not immediately respond to a request for comment.

That law, which follows guidelines by the federal Substance Abuse and Mental Health Services Administration, prohibits employers from levying a "negative employment consequence" against workers for tests that show marijuana levels below 50 nanograms per milliliter. The goal is to prevent employees from being punished for a false positive, which studies have shown could be possible due to inhaling second-hand marijuana smoke.

DeSalvo had been on the force for two and a half years on Jan. 20, 2012, when he and his partner were arresting a combative suspect. The suspect struck DeSalvo in the head, causing a laceration.

DeSalvo sought treatment at Tulane Medical Center, where he also submitted to a post-accident drug screen, which is standard NOPD policy for officers hurt on the job.

Four days later, the test results came back positive. The next day, he paid privately for additional tests of both his urine and hair. Both turned up negative.

He was fired June 5, 2012. He appealed his firing to the Civil Service Commission, which heard his case in May 2013. He argued that the injury was not his fault, so he should not be punished for it. He also argued that he had always tested negative in previous random drug tests and in the subsequent private tests.

A laboratory drug-testing expert testified for the city that DeSalvo's post-injury test was valid.

The Civil Service Commission upheld his firing in September 2013. The city "has a legitimate governmental interest in testing safety sensitive employees who sustain work related injuries," the commission wrote.

There was no evidence that his test was a false positive, and the "fact that (Desalvo) tested negative five days later merely seems to indicate that he did not use marijuana between the initial and subsequent drug screens," wrote Commission Chairman the Rev. Kevin Wildes in the Sept. 6, 2013 opinion, with commissioners Amy Glovinsky and Joseph Clark agreeing.

In reversing that ruling, 4th Circuit Chief Judge James McKay III wrote in the court's opinion that DeSalvo's initial test, at 43 nanograms per milliliter, showed a "relatively small amount of marijuana metabolites."

"Some controversy exists whether a urine sample which tests less than 50 ng/ml should even be considered as a positive result," he wrote. Plus, DeSalvo's previous negative tests and his hair test showed he was not a "habitual or long term user of marijuana."

The panel also included Judges Paul Bonin and Rosemary Ledet. Bonin wrote a separate concurring opinion, adding that the NOPD's use of the positive test results "contravenes the clear dictates of law."

DeSalvo's attorney, Kevin Boshea, did not immediately comment on the ruling.

Just weeks before he was injured on the job, DeSalvo was the subject of a profile by The Atlantic magazine. The article said that the then-23-year-old cop "prides himself on confiscating guns" and had gotten 21 off the streets in the eight months since he started work on a proactive patrol in the NOPD's 5th District, which covers St. Claude, Bywater and the 9th Ward.